Method and apparatus of telephonic communication



April. 1, 1930. s1 RUBEN METHOD AND AFPARATUS 0F .TELEPHONIC C OMMUN ICATION Filed April 8, 1922 INVENTOR ATTORNEY Patented Apr. 1, 1930 UNITED STATES PATENT OFFICE SAMUEL RUBEN, 01 NEW YORK, N. Y., ASSIGNOR '10 RUBEN PATENTS COMPANY, OF NEW YOBK, N. Y., A CORPORATIONOF DELAWARE Mari-r01), ND APPARATUS or rELErnomo commomcA'rrfm Application filed April 8,

The sound waves-electrically transmitted by the commonly employed telephone systems of communication are reproduced by electrically 1 moving or vibrating a diaphragm at a rate corresponding to the variations in the current actuating an element in the circuit, such as an electro magnet, the vibrations of the diaphragm, causing the surroundmg gas to vibrate; thus partially reproducingthe transmitted waves. In all of such systems there is a distortion of the qualities of the transmitted sound due to the incapacity of the diaphragm to vibrate to the-full range of frequencies and other characteristics of the sound waves. I 0 By this invention, no such physical 11mitations exist; there are no diaphragms or other movable mechanical elements. Broadly, this apparatus is composed of a thermionic emission element and a cooperatlng anode element closely spaced therefrom, with means for varying the volume of partiallyconfined gas within the space, in acoustlc vlbrations in response to potential variations of a ourrent at audio frequency impressed upon'the cathode-anode circuit.

The gas in thethermionic field of the receiving apparatus expands and contractsun response to audio frequency current varlatlons applied to its circuit, due to the expenditure upon the conductive field ofthe energy 1nduced by the current variations. The effect of such electrical impulse variations upon the conductive field of the receiving apparatus 1s the emission of sound waves.

It is therefore a principal object of this invention to utilize electrical impulses at audio frequency impressed upon a gas in the field of a thermionic discharge, to produce acous- 1922. Serial m5. 550,850.

tic vibrations of that gas, with minimum distortion and loss of energy. c When electrodes are connected in a circuit and a potential applied to them, one or both being sufliciently heated and the cathode pref= erably coated with an oxide of high electronic emission, there will be a conductive current, or thermionic discharge, through the conductive field or space between them. The gas in the field is thus ionized and heated by that discharge. While the ionizing means described is useful and of practical form, efiicient ionization maybehad by other means, such as by a flame.

An apparatus constructed according to the terms of this invention comprises broad-. ly, a cathode with means for heating it to an emission temperature and, closely spaced from it, an anode connected to it in an exterf nal circuit, and thermally and electrically insulated, the partially closed restricted space between. those elements 0 'ening into a sound directing device, means eing provided for impressing electrical impulses upon the ionized circuit, In one practical form of the invention, the cathode, or emission element is in a partially closed vessel, and is exteriorly coated with an alkaline earth oxide, and closely spaced from theanode element.. As the cathode issufiiciently heated and a high potential ismaintained between those elements, the gas in the intervening s ace is rarefied and'ionized. The volume 0 gas varies with its temperature and with the current discharging through it, the discharge varying so with the electrical, impulses impressed upon the anode. circuit, the response to which is acoustic -vibrations or .sound'waves emitted according to the gas movement into and from the restricted space. That is, .as variations occur'in the potential between the electrodes in response to variations in the electrical impulses impressed upon the anode circuit, cor'- responding variations occur in the gas volume'in the field of the thermionic discharge,

the gas expanding and contracting iii the same frequency and with the same character istics as those of'the applied potential, and thereby producing corresponding acoustic vibrations, which are emitted through a directing funnel or horn.

In the drawings referred to, r Fig.1is-a diagrammatic illustration of the apparatus in a wire circuit, showing the ar- 1 rangement of the electrodes in the transmit- V ter and in the receiver apparatus.

paratus, w

Fig. 2 represents the same system and "apill the addition of an amplifying ineansin the circuit.

field. The trans which isconnected to the receiving or sound emitting device of the system. 6 being the I ionizing element ofthe opposing electrodes, being an electrode in the form of a plate, 8 the source of energy oftheionizing. fel'em'ent.

so;- -of'which is connected to the electrodes, (land *7, in the receiver'housing, the primary of this In Fig. 2, 9 is a transformer, the secondary transformer being connected to a vacuum {tube amplifier, 11, such as is commonly used 'for'this purpose, the source of potential there for, being battery, 10, the energy for the emission element being supplied by battery, 12,

and '13 being the resistance for the control of the current of that'element. 14; represents the housing for the transmitter and 15, the

housing with its horn for the receiver, and- 16 represents the point at which an amplif v ing meansflan be connected in a wire circuit if a receiver islo be employed independently of the transmitter.

- In operation, referring to Fig. 1. when the ionizing element 2 is heated by battery 3 and a potential ds applied by battery 4 across the elements 1 and 2 through the primary of transformer'f the gas between .the electrodes is ionized, and a current flows through the gaseous field thereof. Pressure fluctuations occur in the mechacally conductive gaseous field between elec-' trodes 1 and 2 in response to the sound waves impressed thereupon through the gauze electrode 1, the conductivity of that field varying accordingly. These fluctuations affect the field potential and, correspondingly, the cur-' rent flow of the circuit of electrode 2, and are reflected through thesecondary of the .transformer'li, in thecirc'uit of electrode 6, supplied by battery 8, and also in the potential of the electrically conductive gaseous field of electrodes 6 and 7 of the receiver.

As that potential varies, the gas in its fieldresponds by pressure fluctuations, .or vibrations, which, having the frequency and other characteristics of the impressed sound waves.

shown in Figure 2 is identicalwith that of Figure 1, \viththe introduction of an amplifying means, suchas is commonly used for this purpose; between the transmitter and the receiver,

The draw ngs show the invention as ap-' plied to a wirecircuit telephonic communiing both the transmitter and the receiver, or either device. The receiver can, by ainplification, be made into a kind speaking device. This form of audio receivingdevice canv be substituted for the commonly used type of receiver in a wire circuit or in'a radio communication system. a

v The receiver can also be constructed for and operated by a constant discharge current between its electrodes. An electrically charged grid or a magnetically operated element inserted in the discharge field, will, with changes in its potential, affect the discharge accordingly, the gas responding in sound wave vibrations.

\Vhat I claim is:

1. An electrical sound emittingapparatus comprising a gas filled container having a sound opening, a hot cathode and anode within said container arranged to efiect ionization of the gas therein, means for discharging thermionic current through said gas, an means'for varying the discharge in accordance with audio signal currents.

2. An electrical sound emitting apparatus comprisinga gas filled container having a sound opening, a cathode and ananode within said container arranged to effect ionization cation system. It can be applied to various uses, such as radio communicat on, employof the gasjtherein, means for discharging a' thermionic current through said gas, means for varying the discharge in accordance with audio signal currents, and means for directing acoustic vibration from said sound opening away from said apparatus.

' 3. An electrical sound emitting apparatus comprising ahousing having an opening and arranged to form an enclosure'communieating with theatmosphere through the said opening only, a pair of electrodes situated within theenclosure, meansfor producing'a thermionic discharge between said electrodes, and'mcans for varying the density of said discharge in accordance with audio signal curing with the atmosphere chiefly through the said opening, an ionic discharge device situated within the enclosure, 9. grid-form control element situated within the enclosure'between the discharge device'and'the opening, and means for varying the potential between the discharge device and the control element in response to audio si a1 currents.

5. An electrical soun emitting-apparatus comprising a housing having a'sound opening therein,an ionizing-electrode and a cooperating electrode situated within the housing, a circuit for said electrodes, andmeans for imposing current variations on the circuit of said electrodes corresponding to the sounds to be emitted.

6. An electrical sound emitting apparatus comprising an ionizing electrode and a oooperating electrode spaced therefrom with an intervening ionizable fluid, and means for varying the potential between the electrodes in accordance with audio-signal currents to produce corresponding variations in pressure in the intervenin fluid.

- 7 An electrica sound emitting apparatus comprising a partially confined fluid body,

an ionizing element and a controlelement in contact with said fluid body, and means for varying the potential between the ionizing and control element in accordance with electrical audio signaling currents.

- 8. An ionic discharge acoustic translating device'comprising a housing having a sound opening therein, an ionic discharge device situated within the housing, and a grid-form control element situated within the housing between-the discharge device and the open 5. The method of translating audio electrical signal currents into acoustic vibrations of the atmosphere which comprises varylng the potential between a hot cathode and an anode in accordance with the variations of the signal currents while surrounded'by a partially confined gaseous body to produce corresponding variations in pressure in said confined gaseous body, and communicating said variations in pressure to the atmosphere.

10. The method of translating audio elec: trical s'ignal'cu'rrents into acoustic vibrations of the air which comprises ionizing between a a hot cathode and an anode, apartially confined body of atmospheric air, and varying the potential between the cathode and anode in accordance with the variations of the signaling currents to produce corresponding variations in-pressure in said fluid.

11. Means for reproducing sound through the medium of an ionized air gap which comprises ahot cathode and a cold.anode separated therefrom and exposed to atmosphere, it source" v of current for said cathode, and means for impressing a current varying in po tential inaccordance with the sound t'o be reproduced, upon the space between said oath ode and anode.

12. Means for reproducing sound comprising a long cathodestrip and a long. anode strip separated therefrom, and means for ionizing the air between said cathode and anode in accordance with the sounds to be reproduced.

13. Means for reproducing sound through the medium of an ionized air gap which comprises a long cathode strip and a long anode strip separated therefrom, a sourceof current for said cathode, and means for impressing a current varying in potentialin accordance with the sounds to be reproduced upon the space between said cathode and anode.

14. Means for reproducing sound comprising a hot cathode and a cold anode separated therefrom, the effective surface areas ofsaid cathode and anode-being great relative to space of separation therebetween, and means cordancewith the'sound to be reproduced upon the space between said cathode and anode. p 16. Means for reproducing sOundQcQInpriS- ing a long hotcathode strip and a long anode strip separated therefrom, and means for ionizing the air between said cathode and anode in accordance with thesounds to be reproduced said cathode and anode, being located in the open air.

17 Means forreproducing sound through the medium of an ionized air gap which comprises a long hot cathode .strip'and a long anode strip separated therefr0m,a source of current for said cathode, and means for impressing a current varying in potential in accordance with the sounds to be reproduced upon the space between said cathode and anode, said cathode and anode being located in the open air.

18. Means for reproducing sound comprising a hot cathode and a cold anode separated therefrom, the effective surface areas of said cathode and anode being great relative to space of separationtherebetween, and means for ionizing the air between said cathode and anode in accordance with the sounds to be reproduced, said cathode and anode being located inthe 0 en air.

19. Means or reproducing sound through the medium of an ionized air gapwhich comprises; a' cathode and a cold anode. separated therefrom, the effective surface areas of said cathode and anode being reat relative to the sliaceof separation there etween,-a source of .current for said cathode, and means for impressing a current varying in potential in accordance with the sound to be reproduced upon the space between said cathode and anode.

20. Means for reproducing sound comprising' a; hot cathode, a. cold anode means for ionizing the air between said electrodesjn accordance with the sounds to be reproduced,

and aloud speaking horn, said electrodes bemg located atthe small end of said horn.

igned at-New York city, in the county of New York and State of New York, this 31st day of March, A. D. 1922.

Y'SAMUEL RUBEN. 

